Null Safety in SP

1import std.io;
2
3class Profile {
4    public string bio;
5    public Profile(string bio) {
6        this.bio = bio;
7    }
8}
9
10class User {
11    public Profile? profile; // Nullable type
12    public User(Profile? p) {
13        this.profile = p;
14    }
15}
16
17fn main() -> void {
18    User u1 = new User(null);
19    User u2 = new User(new Profile("Systems Architect"));
20    
21    // 1. Safe Navigation Operator (?.)
22    string? bio1 = u1.profile?.bio;
23    string? bio2 = u2.profile?.bio;
24    
25    // 2. Null Coalescing Operator (??)
26    string displayBio = bio1 ?? "No biography provided";
27    
28    println("User 1 Bio: ${displayBio}");
29    println("User 2 Bio: ${bio2 ?? 'Default'}");
30}